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  • Committer: Björn Påhlsson
  • Date: 2008-07-20 02:52:20 UTC
  • Revision ID: belorn@braxen-20080720025220-r5u0388uy9iu23h6
Added following support:
Pluginbased client handler
rewritten Mandos client
       Avahi instead of udp server discovery
       openpgp encrypted key support
Passprompt stand alone application for direct console input
Added logging for Mandos server

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server.py
1
1
#!/usr/bin/python
2
 
# -*- mode: python; coding: utf-8 -*-
3
 
# 
4
 
# Mandos server - give out binary blobs to connecting clients.
5
 
# 
6
 
# This program is partly derived from an example program for an Avahi
7
 
# service publisher, downloaded from
8
 
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
9
 
# methods "add" and "remove" in the "AvahiService" class, the
10
 
# "server_state_changed" and "entry_group_state_changed" functions,
11
 
# and some lines in "main".
12
 
# 
13
 
# Everything else is
14
 
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
15
 
# 
16
 
# This program is free software: you can redistribute it and/or modify
17
 
# it under the terms of the GNU General Public License as published by
18
 
# the Free Software Foundation, either version 3 of the License, or
19
 
# (at your option) any later version.
20
 
#
21
 
#     This program is distributed in the hope that it will be useful,
22
 
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
23
 
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24
 
#     GNU General Public License for more details.
25
 
# 
26
 
# You should have received a copy of the GNU General Public License
27
 
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
28
 
# 
29
 
# Contact the authors at <mandos@fukt.bsnet.se>.
30
 
# 
31
2
 
32
3
from __future__ import division
33
4
 
50
21
import signal
51
22
from sets import Set
52
23
import subprocess
53
 
import atexit
54
 
import stat
55
 
import logging
56
 
import logging.handlers
57
24
 
58
25
import dbus
59
26
import gobject
61
28
from dbus.mainloop.glib import DBusGMainLoop
62
29
import ctypes
63
30
 
 
31
import logging
 
32
import logging.handlers
 
33
 
 
34
# logghandler.setFormatter(logging.Formatter('%(levelname)s %(message)s')
64
35
 
65
36
logger = logging.Logger('mandos')
66
 
syslogger = logging.handlers.SysLogHandler\
67
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
68
 
             address = "/dev/log")
69
 
syslogger.setFormatter(logging.Formatter\
70
 
                        ('Mandos: %(levelname)s: %(message)s'))
71
 
logger.addHandler(syslogger)
72
 
 
73
 
 
74
 
class AvahiError(Exception):
75
 
    def __init__(self, value):
76
 
        self.value = value
77
 
    def __str__(self):
78
 
        return repr(self.value)
79
 
 
80
 
class AvahiServiceError(AvahiError):
81
 
    pass
82
 
 
83
 
class AvahiGroupError(AvahiError):
84
 
    pass
85
 
 
86
 
 
87
 
class AvahiService(object):
88
 
    """An Avahi (Zeroconf) service.
89
 
    Attributes:
90
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
91
 
               Used to optionally bind to the specified interface.
92
 
    name: string; Example: 'Mandos'
93
 
    type: string; Example: '_mandos._tcp'.
94
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
95
 
    port: integer; what port to announce
96
 
    TXT: list of strings; TXT record for the service
97
 
    domain: string; Domain to publish on, default to .local if empty.
98
 
    host: string; Host to publish records for, default is localhost
99
 
    max_renames: integer; maximum number of renames
100
 
    rename_count: integer; counter so we only rename after collisions
101
 
                  a sensible number of times
102
 
    """
103
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
104
 
                 type = None, port = None, TXT = None, domain = "",
105
 
                 host = "", max_renames = 32768):
106
 
        self.interface = interface
107
 
        self.name = name
108
 
        self.type = type
109
 
        self.port = port
110
 
        if TXT is None:
111
 
            self.TXT = []
112
 
        else:
113
 
            self.TXT = TXT
114
 
        self.domain = domain
115
 
        self.host = host
116
 
        self.rename_count = 0
117
 
    def rename(self):
118
 
        """Derived from the Avahi example code"""
119
 
        if self.rename_count >= self.max_renames:
120
 
            logger.critical(u"No suitable service name found after %i"
121
 
                            u" retries, exiting.", rename_count)
122
 
            raise AvahiServiceError("Too many renames")
123
 
        name = server.GetAlternativeServiceName(name)
124
 
        logger.error(u"Changing name to %r ...", name)
125
 
        syslogger.setFormatter(logging.Formatter\
126
 
                               ('Mandos (%s): %%(levelname)s:'
127
 
                               ' %%(message)s' % name))
128
 
        self.remove()
129
 
        self.add()
130
 
        self.rename_count += 1
131
 
    def remove(self):
132
 
        """Derived from the Avahi example code"""
133
 
        if group is not None:
134
 
            group.Reset()
135
 
    def add(self):
136
 
        """Derived from the Avahi example code"""
137
 
        global group
138
 
        if group is None:
139
 
            group = dbus.Interface\
140
 
                    (bus.get_object(avahi.DBUS_NAME,
141
 
                                    server.EntryGroupNew()),
142
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
143
 
            group.connect_to_signal('StateChanged',
144
 
                                    entry_group_state_changed)
145
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
146
 
                     service.name, service.type)
147
 
        group.AddService(
148
 
                self.interface,         # interface
149
 
                avahi.PROTO_INET6,      # protocol
150
 
                dbus.UInt32(0),         # flags
151
 
                self.name, self.type,
152
 
                self.domain, self.host,
153
 
                dbus.UInt16(self.port),
154
 
                avahi.string_array_to_txt_array(self.TXT))
155
 
        group.Commit()
156
 
 
157
 
# From the Avahi example code:
158
 
group = None                            # our entry group
 
37
logger.addHandler(logging.handlers.SysLogHandler(facility = logging.handlers.SysLogHandler.LOG_DAEMON))
 
38
 
 
39
# This variable is used to optionally bind to a specified interface.
 
40
# It is a global variable to fit in with the other variables from the
 
41
# Avahi server example code.
 
42
serviceInterface = avahi.IF_UNSPEC
 
43
# From the Avahi server example code:
 
44
serviceName = "Mandos"
 
45
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
46
servicePort = None                      # Not known at startup
 
47
serviceTXT = []                         # TXT record for the service
 
48
domain = ""                  # Domain to publish on, default to .local
 
49
host = ""          # Host to publish records for, default to localhost
 
50
group = None #our entry group
 
51
rename_count = 12       # Counter so we only rename after collisions a
 
52
                        # sensible number of times
159
53
# End of Avahi example code
160
54
 
161
55
 
166
60
    fingerprint: string (40 or 32 hexadecimal digits); used to
167
61
                 uniquely identify the client
168
62
    secret:    bytestring; sent verbatim (over TLS) to client
169
 
    host:      string; available for use by the checker command
170
 
    created:   datetime.datetime(); object creation, not client host
171
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
172
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
173
 
                                     until this client is invalid
 
63
    fqdn:      string (FQDN); available for use by the checker command
 
64
    created:   datetime.datetime()
 
65
    last_seen: datetime.datetime() or None if not yet seen
 
66
    timeout:   datetime.timedelta(); How long from last_seen until
 
67
                                     this client is invalid
174
68
    interval:  datetime.timedelta(); How often to start a new checker
175
69
    stop_hook: If set, called by stop() as stop_hook(self)
176
70
    checker:   subprocess.Popen(); a running checker process used
177
71
                                   to see if the client lives.
178
 
                                   'None' if no process is running.
 
72
                                   Is None if no process is running.
179
73
    checker_initiator_tag: a gobject event source tag, or None
180
74
    stop_initiator_tag:    - '' -
181
75
    checker_callback_tag:  - '' -
182
76
    checker_command: string; External command which is run to check if
183
 
                     client lives.  %() expansions are done at
 
77
                     client lives.  %()s expansions are done at
184
78
                     runtime with vars(self) as dict, so that for
185
79
                     instance %(name)s can be used in the command.
186
80
    Private attibutes:
187
81
    _timeout: Real variable for 'timeout'
188
82
    _interval: Real variable for 'interval'
189
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
83
    _timeout_milliseconds: Used by gobject.timeout_add()
190
84
    _interval_milliseconds: - '' -
191
85
    """
192
86
    def _set_timeout(self, timeout):
212
106
    interval = property(lambda self: self._interval,
213
107
                        _set_interval)
214
108
    del _set_interval
215
 
    def __init__(self, name = None, stop_hook=None, config={}):
216
 
        """Note: the 'checker' key in 'config' sets the
217
 
        'checker_command' attribute and *not* the 'checker'
218
 
        attribute."""
 
109
    def __init__(self, name=None, options=None, stop_hook=None,
 
110
                 fingerprint=None, secret=None, secfile=None, fqdn=None,
 
111
                 timeout=None, interval=-1, checker=None):
219
112
        self.name = name
220
 
        logger.debug(u"Creating client %r", self.name)
221
 
        # Uppercase and remove spaces from fingerprint for later
222
 
        # comparison purposes with return value from the fingerprint()
223
 
        # function
224
 
        self.fingerprint = config["fingerprint"].upper()\
225
 
                           .replace(u" ", u"")
226
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
227
 
        if "secret" in config:
228
 
            self.secret = config["secret"].decode(u"base64")
229
 
        elif "secfile" in config:
230
 
            sf = open(config["secfile"])
 
113
        # Uppercase and remove spaces from fingerprint
 
114
        # for later comparison purposes with return value of
 
115
        # the fingerprint() function
 
116
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
 
117
        if secret:
 
118
            self.secret = secret.decode(u"base64")
 
119
        elif secfile:
 
120
            sf = open(secfile)
231
121
            self.secret = sf.read()
232
122
            sf.close()
233
123
        else:
234
 
            raise TypeError(u"No secret or secfile for client %s"
235
 
                            % self.name)
236
 
        self.host = config.get("host", "")
 
124
            raise RuntimeError(u"No secret or secfile for client %s"
 
125
                               % self.name)
 
126
        self.fqdn = fqdn                # string
237
127
        self.created = datetime.datetime.now()
238
 
        self.last_checked_ok = None
239
 
        self.timeout = string_to_delta(config["timeout"])
240
 
        self.interval = string_to_delta(config["interval"])
 
128
        self.last_seen = None
 
129
        if timeout is None:
 
130
            timeout = options.timeout
 
131
        self.timeout = timeout
 
132
        if interval == -1:
 
133
            interval = options.interval
 
134
        else:
 
135
            interval = string_to_delta(interval)
 
136
        self.interval = interval
241
137
        self.stop_hook = stop_hook
242
138
        self.checker = None
243
139
        self.checker_initiator_tag = None
244
140
        self.stop_initiator_tag = None
245
141
        self.checker_callback_tag = None
246
 
        self.check_command = config["checker"]
 
142
        self.check_command = checker
247
143
    def start(self):
248
 
        """Start this client's checker and timeout hooks"""
 
144
        """Start this clients checker and timeout hooks"""
249
145
        # Schedule a new checker to be started an 'interval' from now,
250
146
        # and every interval from then on.
251
147
        self.checker_initiator_tag = gobject.timeout_add\
259
155
                                   self.stop)
260
156
    def stop(self):
261
157
        """Stop this client.
262
 
        The possibility that a client might be restarted is left open,
263
 
        but not currently used."""
264
 
        # If this client doesn't have a secret, it is already stopped.
265
 
        if hasattr(self, "secret") and self.secret:
266
 
            logger.info(u"Stopping client %s", self.name)
267
 
            self.secret = None
268
 
        else:
269
 
            return False
270
 
        if getattr(self, "stop_initiator_tag", False):
 
158
        The possibility that this client might be restarted is left
 
159
        open, but not currently used."""
 
160
        logger.debug(u"Stopping client %s", self.name)
 
161
        self.secret = None
 
162
        if self.stop_initiator_tag:
271
163
            gobject.source_remove(self.stop_initiator_tag)
272
164
            self.stop_initiator_tag = None
273
 
        if getattr(self, "checker_initiator_tag", False):
 
165
        if self.checker_initiator_tag:
274
166
            gobject.source_remove(self.checker_initiator_tag)
275
167
            self.checker_initiator_tag = None
276
168
        self.stop_checker()
279
171
        # Do not run this again if called by a gobject.timeout_add
280
172
        return False
281
173
    def __del__(self):
282
 
        self.stop_hook = None
283
 
        self.stop()
 
174
        # Some code duplication here and in stop()
 
175
        if hasattr(self, "stop_initiator_tag") \
 
176
               and self.stop_initiator_tag:
 
177
            gobject.source_remove(self.stop_initiator_tag)
 
178
            self.stop_initiator_tag = None
 
179
        if hasattr(self, "checker_initiator_tag") \
 
180
               and self.checker_initiator_tag:
 
181
            gobject.source_remove(self.checker_initiator_tag)
 
182
            self.checker_initiator_tag = None
 
183
        self.stop_checker()
284
184
    def checker_callback(self, pid, condition):
285
185
        """The checker has completed, so take appropriate actions."""
286
186
        now = datetime.datetime.now()
287
 
        self.checker_callback_tag = None
288
 
        self.checker = None
289
187
        if os.WIFEXITED(condition) \
290
188
               and (os.WEXITSTATUS(condition) == 0):
291
 
            logger.info(u"Checker for %(name)s succeeded",
292
 
                        vars(self))
293
 
            self.last_checked_ok = now
 
189
            logger.debug(u"Checker for %(name)s succeeded",
 
190
                         vars(self))
 
191
            self.last_seen = now
294
192
            gobject.source_remove(self.stop_initiator_tag)
295
193
            self.stop_initiator_tag = gobject.timeout_add\
296
194
                                      (self._timeout_milliseconds,
297
195
                                       self.stop)
298
 
        elif not os.WIFEXITED(condition):
 
196
        if not os.WIFEXITED(condition):
299
197
            logger.warning(u"Checker for %(name)s crashed?",
300
198
                           vars(self))
301
199
        else:
302
 
            logger.info(u"Checker for %(name)s failed",
303
 
                        vars(self))
 
200
            logger.debug(u"Checker for %(name)s failed",
 
201
                         vars(self))
 
202
            self.checker = None
 
203
        self.checker_callback_tag = None
304
204
    def start_checker(self):
305
205
        """Start a new checker subprocess if one is not running.
306
206
        If a checker already exists, leave it running and do
307
207
        nothing."""
308
 
        # The reason for not killing a running checker is that if we
309
 
        # did that, then if a checker (for some reason) started
310
 
        # running slowly and taking more than 'interval' time, the
311
 
        # client would inevitably timeout, since no checker would get
312
 
        # a chance to run to completion.  If we instead leave running
313
 
        # checkers alone, the checker would have to take more time
314
 
        # than 'timeout' for the client to be declared invalid, which
315
 
        # is as it should be.
316
208
        if self.checker is None:
 
209
            logger.debug(u"Starting checker for %s",
 
210
                         self.name)
317
211
            try:
318
 
                # In case check_command has exactly one % operator
319
 
                command = self.check_command % self.host
 
212
                command = self.check_command % self.fqdn
320
213
            except TypeError:
321
 
                # Escape attributes for the shell
322
214
                escaped_attrs = dict((key, re.escape(str(val)))
323
215
                                     for key, val in
324
216
                                     vars(self).iteritems())
325
217
                try:
326
218
                    command = self.check_command % escaped_attrs
327
219
                except TypeError, error:
328
 
                    logger.error(u'Could not format string "%s":'
329
 
                                 u' %s', self.check_command, error)
 
220
                    logger.critical(u'Could not format string "%s": %s',
 
221
                                    self.check_command, error)
330
222
                    return True # Try again later
331
223
            try:
332
 
                logger.info(u"Starting checker %r for %s",
333
 
                            command, self.name)
334
 
                self.checker = subprocess.Popen(command,
335
 
                                                close_fds=True,
336
 
                                                shell=True, cwd="/")
337
 
                self.checker_callback_tag = gobject.child_watch_add\
338
 
                                            (self.checker.pid,
339
 
                                             self.checker_callback)
 
224
                self.checker = subprocess.\
 
225
                               Popen(command,
 
226
                                     stdout=subprocess.PIPE,
 
227
                                     close_fds=True, shell=True,
 
228
                                     cwd="/")
 
229
                self.checker_callback_tag = gobject.\
 
230
                                            child_watch_add(self.checker.pid,
 
231
                                                            self.\
 
232
                                                            checker_callback)
340
233
            except subprocess.OSError, error:
341
234
                logger.error(u"Failed to start subprocess: %s",
342
235
                             error)
344
237
        return True
345
238
    def stop_checker(self):
346
239
        """Force the checker process, if any, to stop."""
347
 
        if self.checker_callback_tag:
348
 
            gobject.source_remove(self.checker_callback_tag)
349
 
            self.checker_callback_tag = None
350
 
        if getattr(self, "checker", None) is None:
 
240
        if not hasattr(self, "checker") or self.checker is None:
351
241
            return
352
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
353
 
        try:
354
 
            os.kill(self.checker.pid, signal.SIGTERM)
355
 
            #os.sleep(0.5)
356
 
            #if self.checker.poll() is None:
357
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
358
 
        except OSError, error:
359
 
            if error.errno != errno.ESRCH: # No such process
360
 
                raise
 
242
        gobject.source_remove(self.checker_callback_tag)
 
243
        self.checker_callback_tag = None
 
244
        os.kill(self.checker.pid, signal.SIGTERM)
 
245
        if self.checker.poll() is None:
 
246
            os.kill(self.checker.pid, signal.SIGKILL)
361
247
        self.checker = None
362
 
    def still_valid(self):
 
248
    def still_valid(self, now=None):
363
249
        """Has the timeout not yet passed for this client?"""
364
 
        now = datetime.datetime.now()
365
 
        if self.last_checked_ok is None:
 
250
        if now is None:
 
251
            now = datetime.datetime.now()
 
252
        if self.last_seen is None:
366
253
            return now < (self.created + self.timeout)
367
254
        else:
368
 
            return now < (self.last_checked_ok + self.timeout)
 
255
            return now < (self.last_seen + self.timeout)
369
256
 
370
257
 
371
258
def peer_certificate(session):
372
 
    "Return the peer's OpenPGP certificate as a bytestring"
373
259
    # If not an OpenPGP certificate...
374
260
    if gnutls.library.functions.gnutls_certificate_type_get\
375
261
            (session._c_object) \
386
272
 
387
273
 
388
274
def fingerprint(openpgp):
389
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
275
    # New empty GnuTLS certificate
 
276
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
277
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
278
        (ctypes.byref(crt))
390
279
    # New GnuTLS "datum" with the OpenPGP public key
391
280
    datum = gnutls.library.types.gnutls_datum_t\
392
281
        (ctypes.cast(ctypes.c_char_p(openpgp),
393
282
                     ctypes.POINTER(ctypes.c_ubyte)),
394
283
         ctypes.c_uint(len(openpgp)))
395
 
    # New empty GnuTLS certificate
396
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
397
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
398
 
        (ctypes.byref(crt))
399
284
    # Import the OpenPGP public key into the certificate
400
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
401
 
                    (crt, ctypes.byref(datum),
402
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
285
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
 
286
        (crt,
 
287
         ctypes.byref(datum),
 
288
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
403
289
    # New buffer for the fingerprint
404
290
    buffer = ctypes.create_string_buffer(20)
405
291
    buffer_length = ctypes.c_size_t()
421
307
    Note: This will run in its own forked process."""
422
308
    
423
309
    def handle(self):
424
 
        logger.info(u"TCP connection from: %s",
 
310
        logger.debug(u"TCP connection from: %s",
425
311
                     unicode(self.client_address))
426
 
        session = gnutls.connection.ClientSession\
427
 
                  (self.request, gnutls.connection.X509Credentials())
428
 
        
429
 
        line = self.request.makefile().readline()
430
 
        logger.debug(u"Protocol version: %r", line)
431
 
        try:
432
 
            if int(line.strip().split()[0]) > 1:
433
 
                raise RuntimeError
434
 
        except (ValueError, IndexError, RuntimeError), error:
435
 
            logger.error(u"Unknown protocol version: %s", error)
436
 
            return
437
 
        
438
 
        # Note: gnutls.connection.X509Credentials is really a generic
439
 
        # GnuTLS certificate credentials object so long as no X.509
440
 
        # keys are added to it.  Therefore, we can use it here despite
441
 
        # using OpenPGP certificates.
 
312
        session = gnutls.connection.ClientSession(self.request,
 
313
                                                  gnutls.connection.\
 
314
                                                  X509Credentials())
442
315
        
443
316
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
444
317
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
445
318
        #                "+DHE-DSS"))
446
 
        priority = "NORMAL"             # Fallback default, since this
447
 
                                        # MUST be set.
448
 
        if self.server.settings["priority"]:
449
 
            priority = self.server.settings["priority"]
 
319
        priority = "SECURE256"
 
320
        
450
321
        gnutls.library.functions.gnutls_priority_set_direct\
451
322
            (session._c_object, priority, None);
452
323
        
453
324
        try:
454
325
            session.handshake()
455
326
        except gnutls.errors.GNUTLSError, error:
456
 
            logger.warning(u"Handshake failed: %s", error)
 
327
            logger.debug(u"Handshake failed: %s", error)
457
328
            # Do not run session.bye() here: the session is not
458
329
            # established.  Just abandon the request.
459
330
            return
460
331
        try:
461
332
            fpr = fingerprint(peer_certificate(session))
462
333
        except (TypeError, gnutls.errors.GNUTLSError), error:
463
 
            logger.warning(u"Bad certificate: %s", error)
 
334
            logger.debug(u"Bad certificate: %s", error)
464
335
            session.bye()
465
336
            return
466
337
        logger.debug(u"Fingerprint: %s", fpr)
467
338
        client = None
468
 
        for c in self.server.clients:
 
339
        for c in clients:
469
340
            if c.fingerprint == fpr:
470
341
                client = c
471
342
                break
472
 
        if not client:
473
 
            logger.warning(u"Client not found for fingerprint: %s",
474
 
                           fpr)
475
 
            session.bye()
476
 
            return
477
343
        # Have to check if client.still_valid(), since it is possible
478
344
        # that the client timed out while establishing the GnuTLS
479
345
        # session.
480
 
        if not client.still_valid():
481
 
            logger.warning(u"Client %(name)s is invalid",
482
 
                           vars(client))
 
346
        if (not client) or (not client.still_valid()):
 
347
            if client:
 
348
                logger.debug(u"Client %(name)s is invalid",
 
349
                             vars(client))
 
350
            else:
 
351
                logger.debug(u"Client not found for fingerprint: %s",
 
352
                             fpr)
483
353
            session.bye()
484
354
            return
485
355
        sent_size = 0
495
365
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
496
366
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
497
367
    Attributes:
498
 
        settings:       Server settings
 
368
        options:        Command line options
499
369
        clients:        Set() of Client objects
500
370
    """
501
371
    address_family = socket.AF_INET6
502
372
    def __init__(self, *args, **kwargs):
503
 
        if "settings" in kwargs:
504
 
            self.settings = kwargs["settings"]
505
 
            del kwargs["settings"]
 
373
        if "options" in kwargs:
 
374
            self.options = kwargs["options"]
 
375
            del kwargs["options"]
506
376
        if "clients" in kwargs:
507
377
            self.clients = kwargs["clients"]
508
378
            del kwargs["clients"]
511
381
        """This overrides the normal server_bind() function
512
382
        to bind to an interface if one was specified, and also NOT to
513
383
        bind to an address or port if they were not specified."""
514
 
        if self.settings["interface"]:
515
 
            # 25 is from /usr/include/asm-i486/socket.h
516
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
384
        if self.options.interface:
 
385
            if not hasattr(socket, "SO_BINDTODEVICE"):
 
386
                # From /usr/include/asm-i486/socket.h
 
387
                socket.SO_BINDTODEVICE = 25
517
388
            try:
518
389
                self.socket.setsockopt(socket.SOL_SOCKET,
519
 
                                       SO_BINDTODEVICE,
520
 
                                       self.settings["interface"])
 
390
                                       socket.SO_BINDTODEVICE,
 
391
                                       self.options.interface)
521
392
            except socket.error, error:
522
393
                if error[0] == errno.EPERM:
523
 
                    logger.error(u"No permission to"
524
 
                                 u" bind to interface %s",
525
 
                                 self.settings["interface"])
 
394
                    logger.warning(u"No permission to"
 
395
                                   u" bind to interface %s",
 
396
                                   self.options.interface)
526
397
                else:
527
398
                    raise error
528
399
        # Only bind(2) the socket if we really need to.
531
402
                in6addr_any = "::"
532
403
                self.server_address = (in6addr_any,
533
404
                                       self.server_address[1])
534
 
            elif not self.server_address[1]:
 
405
            elif self.server_address[1] is None:
535
406
                self.server_address = (self.server_address[0],
536
407
                                       0)
537
 
#                 if self.settings["interface"]:
538
 
#                     self.server_address = (self.server_address[0],
539
 
#                                            0, # port
540
 
#                                            0, # flowinfo
541
 
#                                            if_nametoindex
542
 
#                                            (self.settings
543
 
#                                             ["interface"]))
544
408
            return super(type(self), self).server_bind()
545
409
 
546
410
 
578
442
    return delta
579
443
 
580
444
 
 
445
def add_service():
 
446
    """From the Avahi server example code"""
 
447
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
448
           domain, host
 
449
    if group is None:
 
450
        group = dbus.Interface(
 
451
                bus.get_object( avahi.DBUS_NAME,
 
452
                                server.EntryGroupNew()),
 
453
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
454
        group.connect_to_signal('StateChanged',
 
455
                                entry_group_state_changed)
 
456
    logger.debug(u"Adding service '%s' of type '%s' ...",
 
457
                 serviceName, serviceType)
 
458
    
 
459
    group.AddService(
 
460
            serviceInterface,           # interface
 
461
            avahi.PROTO_INET6,          # protocol
 
462
            dbus.UInt32(0),             # flags
 
463
            serviceName, serviceType,
 
464
            domain, host,
 
465
            dbus.UInt16(servicePort),
 
466
            avahi.string_array_to_txt_array(serviceTXT))
 
467
    group.Commit()
 
468
 
 
469
 
 
470
def remove_service():
 
471
    """From the Avahi server example code"""
 
472
    global group
 
473
    
 
474
    if not group is None:
 
475
        group.Reset()
 
476
 
 
477
 
581
478
def server_state_changed(state):
582
 
    """Derived from the Avahi example code"""
 
479
    """From the Avahi server example code"""
583
480
    if state == avahi.SERVER_COLLISION:
584
 
        logger.error(u"Server name collision")
585
 
        service.remove()
 
481
        logger.warning(u"Server name collision")
 
482
        remove_service()
586
483
    elif state == avahi.SERVER_RUNNING:
587
 
        service.add()
 
484
        add_service()
588
485
 
589
486
 
590
487
def entry_group_state_changed(state, error):
591
 
    """Derived from the Avahi example code"""
 
488
    """From the Avahi server example code"""
 
489
    global serviceName, server, rename_count
 
490
    
592
491
    logger.debug(u"state change: %i", state)
593
492
    
594
493
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
595
494
        logger.debug(u"Service established.")
596
495
    elif state == avahi.ENTRY_GROUP_COLLISION:
597
 
        logger.warning(u"Service name collision.")
598
 
        service.rename()
 
496
        
 
497
        rename_count = rename_count - 1
 
498
        if rename_count > 0:
 
499
            name = server.GetAlternativeServiceName(name)
 
500
            logger.warning(u"Service name collision, "
 
501
                           u"changing name to '%s' ...", name)
 
502
            remove_service()
 
503
            add_service()
 
504
            
 
505
        else:
 
506
            logger.error(u"No suitable service name found "
 
507
                         u"after %i retries, exiting.",
 
508
                         n_rename)
 
509
            main_loop.quit()
599
510
    elif state == avahi.ENTRY_GROUP_FAILURE:
600
 
        logger.critical(u"Error in group state changed %s",
601
 
                        unicode(error))
602
 
        raise AvahiGroupError("State changed: %s", str(error))
 
511
        logger.error(u"Error in group state changed %s",
 
512
                     unicode(error))
 
513
        main_loop.quit()
 
514
        return
 
515
 
603
516
 
604
517
def if_nametoindex(interface):
605
 
    """Call the C function if_nametoindex(), or equivalent"""
606
 
    global if_nametoindex
 
518
    """Call the C function if_nametoindex()"""
607
519
    try:
608
 
        if "ctypes.util" not in sys.modules:
609
 
            import ctypes.util
610
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
611
 
            (ctypes.util.find_library("c")).if_nametoindex
 
520
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
521
        return libc.if_nametoindex(interface)
612
522
    except (OSError, AttributeError):
613
523
        if "struct" not in sys.modules:
614
524
            import struct
615
525
        if "fcntl" not in sys.modules:
616
526
            import fcntl
617
 
        def if_nametoindex(interface):
618
 
            "Get an interface index the hard way, i.e. using fcntl()"
619
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
620
 
            s = socket.socket()
621
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
622
 
                                struct.pack("16s16x", interface))
623
 
            s.close()
624
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
625
 
            return interface_index
626
 
    return if_nametoindex(interface)
627
 
 
628
 
 
629
 
def daemon(nochdir = False, noclose = False):
630
 
    """See daemon(3).  Standard BSD Unix function.
631
 
    This should really exist as os.daemon, but it doesn't (yet)."""
632
 
    if os.fork():
633
 
        sys.exit()
634
 
    os.setsid()
635
 
    if not nochdir:
636
 
        os.chdir("/")
637
 
    if os.fork():
638
 
        sys.exit()
639
 
    if not noclose:
640
 
        # Close all standard open file descriptors
641
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
642
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
643
 
            raise OSError(errno.ENODEV,
644
 
                          "/dev/null not a character device")
645
 
        os.dup2(null, sys.stdin.fileno())
646
 
        os.dup2(null, sys.stdout.fileno())
647
 
        os.dup2(null, sys.stderr.fileno())
648
 
        if null > 2:
649
 
            os.close(null)
650
 
 
651
 
 
652
 
def main():
653
 
    global main_loop_started
654
 
    main_loop_started = False
655
 
    
 
527
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
528
        s = socket.socket()
 
529
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
530
                            struct.pack("16s16x", interface))
 
531
        s.close()
 
532
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
533
        return interface_index
 
534
 
 
535
 
 
536
if __name__ == '__main__':
656
537
    parser = OptionParser()
657
538
    parser.add_option("-i", "--interface", type="string",
658
 
                      metavar="IF", help="Bind to interface IF")
659
 
    parser.add_option("-a", "--address", type="string",
660
 
                      help="Address to listen for requests on")
661
 
    parser.add_option("-p", "--port", type="int",
 
539
                      default=None, metavar="IF",
 
540
                      help="Bind to interface IF")
 
541
    parser.add_option("--cert", type="string", default="cert.pem",
 
542
                      metavar="FILE",
 
543
                      help="Public key certificate PEM file to use")
 
544
    parser.add_option("--key", type="string", default="key.pem",
 
545
                      metavar="FILE",
 
546
                      help="Private key PEM file to use")
 
547
    parser.add_option("--ca", type="string", default="ca.pem",
 
548
                      metavar="FILE",
 
549
                      help="Certificate Authority certificate PEM file to use")
 
550
    parser.add_option("--crl", type="string", default="crl.pem",
 
551
                      metavar="FILE",
 
552
                      help="Certificate Revokation List PEM file to use")
 
553
    parser.add_option("-p", "--port", type="int", default=None,
662
554
                      help="Port number to receive requests on")
 
555
    parser.add_option("--timeout", type="string", # Parsed later
 
556
                      default="1h",
 
557
                      help="Amount of downtime allowed for clients")
 
558
    parser.add_option("--interval", type="string", # Parsed later
 
559
                      default="5m",
 
560
                      help="How often to check that a client is up")
663
561
    parser.add_option("--check", action="store_true", default=False,
664
562
                      help="Run self-test")
665
 
    parser.add_option("--debug", action="store_true",
666
 
                      help="Debug mode; run in foreground and log to"
667
 
                      " terminal")
668
 
    parser.add_option("--priority", type="string", help="GnuTLS"
669
 
                      " priority string (see GnuTLS documentation)")
670
 
    parser.add_option("--servicename", type="string", metavar="NAME",
671
 
                      help="Zeroconf service name")
672
 
    parser.add_option("--configdir", type="string",
673
 
                      default="/etc/mandos", metavar="DIR",
674
 
                      help="Directory to search for configuration"
675
 
                      " files")
 
563
    parser.add_option("--debug", action="store_true", default=False,
 
564
                      help="Debug mode")
676
565
    (options, args) = parser.parse_args()
677
566
    
678
567
    if options.check:
680
569
        doctest.testmod()
681
570
        sys.exit()
682
571
    
683
 
    # Default values for config file for server-global settings
684
 
    server_defaults = { "interface": "",
685
 
                        "address": "",
686
 
                        "port": "",
687
 
                        "debug": "False",
688
 
                        "priority":
689
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
690
 
                        "servicename": "Mandos",
691
 
                        }
692
 
    
693
 
    # Parse config file for server-global settings
694
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
695
 
    del server_defaults
696
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
697
 
    server_section = "server"
698
 
    # Convert the SafeConfigParser object to a dict
699
 
    server_settings = dict(server_config.items(server_section))
700
 
    # Use getboolean on the boolean config option
701
 
    server_settings["debug"] = server_config.getboolean\
702
 
                               (server_section, "debug")
703
 
    del server_config
704
 
    
705
 
    # Override the settings from the config file with command line
706
 
    # options, if set.
707
 
    for option in ("interface", "address", "port", "debug",
708
 
                   "priority", "servicename", "configdir"):
709
 
        value = getattr(options, option)
710
 
        if value is not None:
711
 
            server_settings[option] = value
712
 
    del options
713
 
    # Now we have our good server settings in "server_settings"
714
 
    
715
 
    debug = server_settings["debug"]
716
 
    
717
 
    if not debug:
718
 
        syslogger.setLevel(logging.WARNING)
719
 
    
720
 
    if server_settings["servicename"] != "Mandos":
721
 
        syslogger.setFormatter(logging.Formatter\
722
 
                               ('Mandos (%s): %%(levelname)s:'
723
 
                                ' %%(message)s'
724
 
                                % server_settings["servicename"]))
725
 
    
726
 
    # Parse config file with clients
727
 
    client_defaults = { "timeout": "1h",
728
 
                        "interval": "5m",
729
 
                        "checker": "fping -q -- %%(host)s",
730
 
                        }
731
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
732
 
    client_config.read(os.path.join(server_settings["configdir"],
733
 
                                    "clients.conf"))
734
 
    
735
 
    global service
736
 
    service = AvahiService(name = server_settings["servicename"],
737
 
                           type = "_mandos._tcp", );
738
 
    if server_settings["interface"]:
739
 
        service.interface = if_nametoindex(server_settings["interface"])
740
 
    
741
 
    global main_loop
742
 
    global bus
743
 
    global server
744
 
    # From the Avahi example code
 
572
    # Parse the time arguments
 
573
    try:
 
574
        options.timeout = string_to_delta(options.timeout)
 
575
    except ValueError:
 
576
        parser.error("option --timeout: Unparseable time")
 
577
    try:
 
578
        options.interval = string_to_delta(options.interval)
 
579
    except ValueError:
 
580
        parser.error("option --interval: Unparseable time")
 
581
    
 
582
    # Parse config file
 
583
    defaults = { "checker": "sleep 1; fping -q -- %%(fqdn)s" }
 
584
    client_config = ConfigParser.SafeConfigParser(defaults)
 
585
    #client_config.readfp(open("secrets.conf"), "secrets.conf")
 
586
    client_config.read("mandos-clients.conf")
 
587
    
 
588
    # From the Avahi server example code
745
589
    DBusGMainLoop(set_as_default=True )
746
590
    main_loop = gobject.MainLoop()
747
591
    bus = dbus.SystemBus()
750
594
            avahi.DBUS_INTERFACE_SERVER )
751
595
    # End of Avahi example code
752
596
    
753
 
    if debug:
754
 
        console = logging.StreamHandler()
755
 
        # console.setLevel(logging.DEBUG)
756
 
        console.setFormatter(logging.Formatter\
757
 
                             ('%(levelname)s: %(message)s'))
758
 
        logger.addHandler(console)
759
 
        del console
 
597
    debug = options.debug
760
598
    
761
599
    clients = Set()
762
600
    def remove_from_clients(client):
763
601
        clients.remove(client)
764
602
        if not clients:
765
 
            logger.critical(u"No clients left, exiting")
766
 
            sys.exit()
 
603
            logger.debug(u"No clients left, exiting")
 
604
            main_loop.quit()
767
605
    
768
 
    clients.update(Set(Client(name = section,
 
606
    clients.update(Set(Client(name=section, options=options,
769
607
                              stop_hook = remove_from_clients,
770
 
                              config
771
 
                              = dict(client_config.items(section)))
 
608
                              **(dict(client_config\
 
609
                                      .items(section))))
772
610
                       for section in client_config.sections()))
773
 
    if not clients:
774
 
        logger.critical(u"No clients defined")
775
 
        sys.exit(1)
776
 
    
777
 
    if not debug:
778
 
        daemon()
779
 
    
780
 
    pidfilename = "/var/run/mandos/mandos.pid"
781
 
    pid = os.getpid()
782
 
    try:
783
 
        pidfile = open(pidfilename, "w")
784
 
        pidfile.write(str(pid) + "\n")
785
 
        pidfile.close()
786
 
        del pidfile
787
 
    except IOError, err:
788
 
        logger.error(u"Could not write %s file with PID %d",
789
 
                     pidfilename, os.getpid())
790
 
    
791
 
    def cleanup():
792
 
        "Cleanup function; run on exit"
793
 
        global group
794
 
        # From the Avahi example code
795
 
        if not group is None:
796
 
            group.Free()
797
 
            group = None
798
 
        # End of Avahi example code
799
 
        
800
 
        while clients:
801
 
            client = clients.pop()
802
 
            client.stop_hook = None
803
 
            client.stop()
804
 
    
805
 
    atexit.register(cleanup)
806
 
    
807
 
    if not debug:
808
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
809
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
810
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
811
 
    
812
611
    for client in clients:
813
612
        client.start()
814
613
    
815
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
816
 
                                 server_settings["port"]),
 
614
    tcp_server = IPv6_TCPServer((None, options.port),
817
615
                                tcp_handler,
818
 
                                settings=server_settings,
 
616
                                options=options,
819
617
                                clients=clients)
820
 
    # Find out what port we got
821
 
    service.port = tcp_server.socket.getsockname()[1]
822
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
823
 
                u" scope_id %d" % tcp_server.socket.getsockname())
824
 
    
825
 
    #service.interface = tcp_server.socket.getsockname()[3]
826
 
    
 
618
    # Find out what random port we got
 
619
    servicePort = tcp_server.socket.getsockname()[1]
 
620
    logger.debug(u"Now listening on port %d", servicePort)
 
621
    
 
622
    if options.interface is not None:
 
623
        serviceInterface = if_nametoindex(options.interface)
 
624
    
 
625
    # From the Avahi server example code
 
626
    server.connect_to_signal("StateChanged", server_state_changed)
 
627
    server_state_changed(server.GetState())
 
628
    # End of Avahi example code
 
629
    
 
630
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
631
                         lambda *args, **kwargs:
 
632
                         tcp_server.handle_request(*args[2:],
 
633
                                                   **kwargs) or True)
827
634
    try:
828
 
        # From the Avahi example code
829
 
        server.connect_to_signal("StateChanged", server_state_changed)
830
 
        try:
831
 
            server_state_changed(server.GetState())
832
 
        except dbus.exceptions.DBusException, error:
833
 
            logger.critical(u"DBusException: %s", error)
834
 
            sys.exit(1)
835
 
        # End of Avahi example code
836
 
        
837
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
838
 
                             lambda *args, **kwargs:
839
 
                             tcp_server.handle_request\
840
 
                             (*args[2:], **kwargs) or True)
841
 
        
842
 
        logger.debug(u"Starting main loop")
843
 
        main_loop_started = True
844
635
        main_loop.run()
845
 
    except AvahiError, error:
846
 
        logger.critical(u"AvahiError: %s" + unicode(error))
847
 
        sys.exit(1)
848
636
    except KeyboardInterrupt:
849
 
        if debug:
850
 
            print
 
637
        print
 
638
    
 
639
    # Cleanup here
851
640
 
852
 
if __name__ == '__main__':
853
 
    main()
 
641
    # From the Avahi server example code
 
642
    if not group is None:
 
643
        group.Free()
 
644
    # End of Avahi example code
 
645
    
 
646
    for client in clients:
 
647
        client.stop_hook = None
 
648
        client.stop()